On the heels of a disastrous 2012, the Big Four are back with big plans to beat cable -- whether it's spending $3 million an episode for "Under the Dome" (CBS) or going cheap with foreign shows.

When CBS unveils its high-concept drama Under the Dome on June 24, viewers will get an opportunity to feast their eyes on something they rarely, if ever, see. The Steven Spielberg-Stephen King drama not only is a scripted original available during a period historically reserved for broadcast repeats and reality, but it's being made at a price point on par with an in-season show rather than at a slashed summer budget.

The move toward year-round originals comes after a summer in which CBS, Fox and ABC were all down double digits (NBC was saved only by the Olympics) and viewers were further incentivized to abandon broadcast for cable's high-profile offerings (see AMC's Breaking Bad and TNT's Falling Skies). "They have to do something," explains Gary Carr, senior vp at media agency TargetCast. "The networks are getting eaten away little by little every year by cable, which basically got going because the networks would put repeats and crap on in the summer."

But the question remains: How to offer originals in a way that's economically feasible at a time of year when viewership and ad money are down? Summer 2013 will test different financial models as the networks attempt to lure viewers back.

CBS is at the more ambitious end of the broadcast spectrum, with the CBS TV Studios-produced Dome budgeted at about $3 million per episode and accompanied by a promotional campaign that included a Super Bowl plug.

To make its summertime push work, CBS is relying on a creative mix of digital and international revenue that is said to make the effort profitable from the outset. The company struck a rich deal with Amazon, which will make episodes of the event series available to Amazon Prime members four days after they air on CBS. In addition, the heavily serialized series, about a town inexplicably sealed off by a giant dome, has been licensed in 200 international markets.

"Show to show, we're going to look at what model best suits producing this kind of show … it's not one size fits all," says CBS entertainment chief Nina Tassler of her summer strategy. Her network also will move its briefly canceled Poppy Montgomery drama Unforgettable to summer, with studio Sony able to maintain the same budget care of international revenue (CBS is said to have shaved its license fee). Tassler's counterpart at CBS TV Studios, David Stapf, already is encouraging his team to drum up noisy options for future summers, with the hope that the buzzy Dome will deliver. Says Stapf: "This is a great show that has event qualities to it, and if it works, it's fulfilling a need that is there."

ABC executive Quinn Taylor acknowledges that he, too, is keeping a close eye on Dome's performance. "I'm really hoping it works because it's another way to tackle summer with a big event," he says. "I know Paul [Lee, president of the ABC Entertainment Group] is on me to do that as well."

Fox is still a year away from joining the summer scripted fray in any meaningful way but it plans to do so with a collection of high-profile limited series (24: Live Another Day, the Matt Dillon/Melissa Leo drama Wayward Pines), which several sources suggest will be even pricier.

At this stage, ABC and NBC won't be shelling out as much on production or promotion, but they are just as aggressive about the need to pepper the summer schedule with new reasons to tune in. This year, the networks both will take a shot at lower-cost originals, including ABC's Mistresses and NBC's Camp.

In contrast to Dome, which features a sizable ensemble of recognizable actors and a big dose of special effects, Camp was shot in Australia with a cast comprised largely of young, unknown local actors and a budget said to be less than $2 million per episode. "The summer, by necessity, has to be low cost, but it's evolving, and we just thought that this was a soapy summer show with a little edge and a little wish fulfillment," NBC entertainment president Jennifer Salke acknowledges.

Increasingly common -- and often more cost-effective -- are the international acquisitions that have come to line the networks in recent years, be it ABC's Canadian co-production Motive and a fourth season of Rookie Blue or NBC's Siberia and Crossing Lines. A straight acquisition can cost the network as little as $250,000 per episode, say multiple sources, but such productions have struggled in the past from lack of buy-in from executives who are more focused on shows they develop. If the network comes in at an early stage and has substantial input, the price tag often is closer to $750,000. And if it's a true co-production, the network will usually shell out between $750,000 and $1 million.

With lower up-front costs and thus considerably less risk, Taylor notes, "It's easier for us to keep them on the schedule at a 1.1 or 1.2 [rating] as opposed to in-season where you've got to have a '2' in front of it."